nbd: cleanup ioctl handling

Break the ioctl handling out into helper functions, some of these things
are getting pretty big and unwieldy.
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

drivers/block/nbd.c

@@ -96,6 +96,10 @@ static int max_part;
 static struct workqueue_struct *recv_workqueue;
 static int part_shift;
 
+static int nbd_dev_dbg_init(struct nbd_device *nbd);
+static void nbd_dev_dbg_close(struct nbd_device *nbd);
+
+
 static inline struct device *nbd_to_dev(struct nbd_device *nbd)
 {
 	return disk_to_dev(nbd->disk);
@@ -571,10 +575,17 @@ static int nbd_queue_rq(struct blk_mq_hw_ctx *hctx,
 	return BLK_MQ_RQ_QUEUE_OK;
 }
 
-static int nbd_add_socket(struct nbd_device *nbd, struct socket *sock)
+static int nbd_add_socket(struct nbd_device *nbd, struct block_device *bdev,
+			  unsigned long arg)
 {
+	struct socket *sock;
 	struct nbd_sock **socks;
 	struct nbd_sock *nsock;
+	int err;
+
+	sock = sockfd_lookup(arg, &err);
+	if (!sock)
+		return err;
 
 	if (!nbd->task_setup)
 		nbd->task_setup = current;
@@ -598,26 +609,20 @@ static int nbd_add_socket(struct nbd_device *nbd, struct socket *sock)
 	nsock->sock = sock;
 	socks[nbd->num_connections++] = nsock;
 
+	if (max_part)
+		bdev->bd_invalidated = 1;
 	return 0;
 }
 
 /* Reset all properties of an NBD device */
 static void nbd_reset(struct nbd_device *nbd)
 {
-	int i;
-
-	for (i = 0; i < nbd->num_connections; i++)
-		kfree(nbd->socks[i]);
-	kfree(nbd->socks);
-	nbd->socks = NULL;
 	nbd->runtime_flags = 0;
 	nbd->blksize = 1024;
 	nbd->bytesize = 0;
 	set_capacity(nbd->disk, 0);
 	nbd->flags = 0;
 	nbd->tag_set.timeout = 0;
-	nbd->num_connections = 0;
-	nbd->task_setup = NULL;
 	queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, nbd->disk->queue);
 }
 
@@ -659,15 +664,8 @@ static void send_disconnects(struct nbd_device *nbd)
 	}
 }
 
-static int nbd_dev_dbg_init(struct nbd_device *nbd);
-static void nbd_dev_dbg_close(struct nbd_device *nbd);
-
-/* Must be called with config_lock held */
-static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
-		       unsigned int cmd, unsigned long arg)
+static int nbd_disconnect(struct nbd_device *nbd, struct block_device *bdev)
 {
-	switch (cmd) {
-	case NBD_DISCONNECT: {
 	dev_info(disk_to_dev(nbd->disk), "NBD_DISCONNECT\n");
 	if (!nbd->socks)
 		return -EINVAL;
@@ -684,9 +682,10 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
 			      &nbd->runtime_flags))
 		send_disconnects(nbd);
 	return 0;
-	}
+}
 
-	case NBD_CLEAR_SOCK:
+static int nbd_clear_sock(struct nbd_device *nbd, struct block_device *bdev)
+{
 	sock_shutdown(nbd);
 	nbd_clear_que(nbd);
 	kill_bdev(bdev);
@@ -695,7 +694,8 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
 	 * We want to give the run thread a chance to wait for everybody
 	 * to clean up and then do it's own cleanup.
 	 */
-		if (!test_bit(NBD_RUNNING, &nbd->runtime_flags)) {
+	if (!test_bit(NBD_RUNNING, &nbd->runtime_flags) &&
+	    nbd->num_connections) {
 		int i;
 
 		for (i = 0; i < nbd->num_connections; i++)
@@ -703,46 +703,14 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
 		kfree(nbd->socks);
 		nbd->socks = NULL;
 		nbd->num_connections = 0;
-			nbd->task_setup = NULL;
-		}
-		return 0;
-
-	case NBD_SET_SOCK: {
-		int err;
-		struct socket *sock = sockfd_lookup(arg, &err);
-
-		if (!sock)
-			return err;
-
-		err = nbd_add_socket(nbd, sock);
-		if (!err && max_part)
-			bdev->bd_invalidated = 1;
-
-		return err;
-	}
-
-	case NBD_SET_BLKSIZE: {
-		loff_t bsize = div_s64(nbd->bytesize, arg);
-
-		return nbd_size_set(nbd, bdev, arg, bsize);
 	}
+	nbd->task_setup = NULL;
 
-	case NBD_SET_SIZE:
-		return nbd_size_set(nbd, bdev, nbd->blksize,
-					div_s64(arg, nbd->blksize));
-
-	case NBD_SET_SIZE_BLOCKS:
-		return nbd_size_set(nbd, bdev, nbd->blksize, arg);
-
-	case NBD_SET_TIMEOUT:
-		nbd->tag_set.timeout = arg * HZ;
-		return 0;
-
-	case NBD_SET_FLAGS:
-		nbd->flags = arg;
 	return 0;
+}
 
-	case NBD_DO_IT: {
+static int nbd_start_device(struct nbd_device *nbd, struct block_device *bdev)
+{
 	struct recv_thread_args *args;
 	int num_connections = nbd->num_connections;
 	int error = 0, i;
@@ -798,10 +766,8 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
 	mutex_lock(&nbd->config_lock);
 	nbd->task_recv = NULL;
 out_err:
-		sock_shutdown(nbd);
-		nbd_clear_que(nbd);
-		kill_bdev(bdev);
-		nbd_bdev_reset(bdev);
+	clear_bit(NBD_RUNNING, &nbd->runtime_flags);
+	nbd_clear_sock(nbd, bdev);
 
 	/* user requested, ignore socket errors */
 	if (test_bit(NBD_DISCONNECT_REQUESTED, &nbd->runtime_flags))
@@ -811,15 +777,44 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
 
 	nbd_reset(nbd);
 	return error;
-	}
+}
 
+/* Must be called with config_lock held */
+static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd,
+		       unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case NBD_DISCONNECT:
+		return nbd_disconnect(nbd, bdev);
+	case NBD_CLEAR_SOCK:
+		return nbd_clear_sock(nbd, bdev);
+	case NBD_SET_SOCK:
+		return nbd_add_socket(nbd, bdev, arg);
+	case NBD_SET_BLKSIZE:
+		return nbd_size_set(nbd, bdev, arg,
+				    div_s64(nbd->bytesize, arg));
+	case NBD_SET_SIZE:
+		return nbd_size_set(nbd, bdev, nbd->blksize,
+					div_s64(arg, nbd->blksize));
+
+	case NBD_SET_SIZE_BLOCKS:
+		return nbd_size_set(nbd, bdev, nbd->blksize, arg);
+
+	case NBD_SET_TIMEOUT:
+		nbd->tag_set.timeout = arg * HZ;
+		return 0;
+
+	case NBD_SET_FLAGS:
+		nbd->flags = arg;
+		return 0;
+	case NBD_DO_IT:
+		return nbd_start_device(nbd, bdev);
 	case NBD_CLEAR_QUE:
 		/*
 		 * This is for compatibility only.  The queue is always cleared
 		 * by NBD_DO_IT or NBD_CLEAR_SOCK.
 		 */
 		return 0;
-
 	case NBD_PRINT_DEBUG:
 		/*
 		 * For compatibility only, we no longer keep a list of